Electrical protective device



March 1938. R. R. PITTMAN ET AL 2,

ELECTRICAL PROTECTIVE DEVICE Filed April 26, 193'? 23. ,mmm

f 23% 4 INVENTORS retested Mar. 1, 193;

UNITED STATES PATENT OFFICE Carroll-H. Walsh, Ark.

application April as, 1937, Serial No. 138,898

(oi. zoo-11s) 'IClalllll- This invention relates to protective devicesfor use in connection with high voltage circuits, and the principalobject is to provide in a compact unit a lightning arrester of theexpulsion type having a path to ground for reducing excessivesuperimposed voltages, and a fuse of the expulsion type fordisconnecting a circuit in the event of excwsive overcurrent therein.

Another object is to provide a unitary assembly in which either theexpulsion arrester or the expulsion fuse, or both, may be readilyremoved for inspection, repair or replacement.

A further object is to provide a device, embodyfuse II, through whichthe fuselink 32 passes, electrically connects the load terminal member34 a with the metal sleet hood IS.

the ground terminal It. Y

The metal line terminal member 2! is attached to the upper surface ofthe sleet hood I! by ing a removably mounted expulsion arrester and aremovably mounted expulsion fuse, in which the gases attending theoperation of both expulsion devices will be discharged in a directionaway from an operator of the device, away from the normally alive parts,and in divergent directions with respect to each other.

with these and other objects in view which will appear from thedescription, our invention resides in the construction and arrangementof parts making up the combination which may be installed and removed asa unit,.and in which the means of the screws 22 and 23, and extends ver-10 tically upward beyond the uppermost portion of the upper insulatorI6. The line terminal 24, at the upper end of the terminal member 2!, isarranged to electrically connect the line conductor 35.

' also rigidly attached to the upper end of the line terminal member 21by the pin 42, the latter exnumber of parts is not only fewer than thoserequired for separately mounted units, but also in which the vitalmembers which are subject to electrical damage are readily removable andreplaceable.

In the drawing, Fig. 1 is a side elevational view of the device in theservice position; Fig. 2 is a fragmentary view of the upper end of thebase,

taken 'along the line lI- -II in Fig. 1; and Fig.3 35 is a rearfragmentarythe base.

Referring first to Fig. 1, a base I. of conducting material, hereindicated as a metal channel, is secured, by means of the attachingbolts and nuts 12 and i3, and the metal strap H, to the wood cross armII, with its-mounting surface 30 thereagainst, the base extendingvertically above and below the cross arm ll.

The vertically spaced upper and lower insulathe base in any suitablemanner. The forwardly extending metal sleet hood ll is secured to theouter end of the upper insulator II by means of 1 the cap screws 20, andsimilarly, the lower metal expulsion fuse support 84 is secured to theouter end of thelower insulator I I by means of the cap sc'rew ll. 3 i

A load conductor 2.. is electrically connected to the lower expulsionfuse support 3,4 by the load terminal I2, and a swingably removableexpulsion view of the upper end of tending through both members.

A portion of the base 10 extends vertically to a point above theupperinsulator l0, and from its 20 upperend a centrally positioned slotll (Figs. 2 and ii) extends downwardly to a point in approximate coaxialalignment with the electrode 2!. The mounting stud of the expulsion typelightning arrester "is positioned at the bottom 25 of the slot ll and isdetachably mounted on the base it by clamping the latter between thebase 21 of the arresterand the screw eye 20, the latter, cooperatingwith threads on the stud Ill. The

arrester may be readily removed by inserting the end of an insulatedswitch hook stick through the eye 29, and rotating it in acounterclockwise direction until it is loosened, and then lifting it oflof the base ll.

A suitable type of expulsion lightning arrester a for use with thepresentinvention is that shown in detail in Patent No. 2,002,042, datedMay 21,

- 1935, and issued to Ralph R. Pittman, one of the inventors herein, anda suitable type of expulsion in detail in our copending applicationSerial No.

tors II and 'II respectively 'are rigidly secured to.

120,962, died January 16, 1987.

Such devices as these, which depend upon the expulsion principle for-arcextinguishment, discharge conducting gas and flame when operatas ing.Upon the solution to the problem of directing such gases to avoid shortcircuits and injury to. workmen depends the success of devices of thenature of the present invention. a

For this reason, theexpulsion arrester II'.is so providedwith the gasconducting and directing vent 2|, integral with thebase 21, fordischargingthegasesinadirectionawayfromtheline termlnflmember 2|, andfromthe leakage pre-l venting air gap formed by the spaced electrodes gsThe horizontally positioned electrode 25 is 15 I 26 and 25. It may bealso observed that this direction of discharge is'away from the positionof a workman operating the expulsion fuse 3i, and divergent with respectto gases discharged from the lower end of the expulsion fuse.

It will be apparent from the above description that either or both theexpulsion arrester I'I and/or the expulsion fuse 3! may be readilyremoved whenever desired with the use of an ordinary switch hook.

From thelembodiment of our invention herein specifically described,other equivalent arrangements will be apparent, and it is to beunderstood that the invention herein is to be limited only as isnecessitated by the prior art and the appended claims.

What we claim is new, and desire to secure by Letters Patent, is:

1. In combination, a base having a mounting surface, and an expulsionfuse and an expulsion arrester carried thereby, said expulsion fuse andexpulsion arrester being so positioned that the gases attending theiroperation is discharged through the plane in which said mounting surfacelies and divergently with respect to each other.

2-. In combination, a base having a mounting surface, and an expulsionfuse and an expulsion lightning arrester removably mounted thereon, saidexpulsion fuse and expulsion arrester being arranged so that the gasesattending the operation of the fuse are discharged in a directiondivergent with respect to the direction of discharge of gases attendingthe operation of the arrester, and so that the direction ofv gasdischarge from each is through the plane in which said mounting surfaceis positioned.

3. A protective device comprising a base of conducting material, upperand lower insulators 4 gnounted in spaced relation on said base, a sleethood of conducting material secured to said upper insulator andextending outwardly therefrom, a line terminal member extending upwardlyfrom said sleet hood, a line terminal secured at the upperend of saidterminal member, a load terminal associated with the lower insulator,means including an expulsion fuse electrically connecting the lineterminal to the load terminal, and an expulsion lightning arresterdetachably mounted on and electrically connected to said base above theupper insulator and extending horizontally therefrom to provide an airgap between said arrester and said line terminal, said arrester havingvent means for directing the discharge of gases attending the operationthereof through the plane in which said base is positioned.

4. A protective device comprising a vertically extending baseofconducting material, spaced upper and lower insulators mounted on saidbase, line and load terminals carried respectively by said upper andlower insulators, means including an expulsion fuse electricallyconnecting said terminals, an expulsion lightning arrester positionedadjacent said upper insulator in spaced relationship with respect tosaid line terminal, and means including a slot in said base extendingdownwardly from the top thereof for removably attaching said expulsionarrester to said base.v

5. A protective device comprising a vertically extending base ofconducting material, spaced upper and lower insulators mounted on saidbase, line and load terminals carried respectively by said upper andlower insulators, means including an expulsion fuse electricallyconnecting said terminals, an expulsion lightning arrester positionedadjacent said upper insulator in spaced relationship with respect tosaid line terminal, a slot in said base extending downwardly from thetop thereof, and adjustable means cooperating with said slot forremovably attaching said the gaseous discharge accompanying itsoperation is directed away from both said line and load terminals. 4

'7. In a protective device, the combination of a common verticallyextending metal base having mounted thereon spaced insulated upper lineand lower. load terminal'members, a removable fuse container pivotallymounted on the load terminal member and in electrical contact with theline terminal member, means including an expulsion lightning arresterextending horizontally from the top of said base in normally insulatedspaced relationship to upper line terminal member for establishing apreferential sparkover path from the latter to the base, and clampingmeans combined with said arrester, said clamping means being arranged toremovably engage said base for supporting said arrester thereon.

RALPH R. PITTMAN. CARROLL H. WALSH.

